A wide variety of liquid compositions involve more two reactive liquid components that must be manufactured, shipped, and stored separately, then combined shortly before use. Some of these components are used to make coatings, such as are used on floors and other substrates.
Once the two reactive components are mixed, they begin to react. As the reaction proceeds, the mixture eventually becomes too viscous to use. The length of time between (i) initial contact and mixing and (ii) viscosity too high to use, is generally referred to as the “pot life” of the mixture.
Various reactants have various storage requirements in order that the reactant has the desired shelf life. Keeping the reactant inside a package and out of contact with reactive components lengthens the shelf life of the component. Reactive components can include air, moisture, other reactants in the system, etc.
Recently a new two-component, alcohol-resistant, chemically-strippable floor coating system has been introduced into the marketplace. This new floor coating system has a first reactive component which is an aqueous polymer dispersion of at least one polyol and at least one wax material, and a second reactive component which includes a polyisocyanate material and at least one organic solvent. The first and second reactive components are designed to react with one another to form an alcohol-resistant, chemically-strippable crosslinked polyurethane coating suitable for use on floors.
The aqueous polymer dispersion of the polyol is provided in a flexible plastic pouch having a removable cap. The polyisocyanate material, which can be rendered inoperative by exposure to even small quantities of water, is provided in a metal can having a removable cap. In order to bring the two components into contact with one another and mix them to uniformity, both the pouch and the can are opened, and the contents of the can are added to the pouch. The need to open the containers and combine the reactive liquid components carries with it the possibility of skin contact with one or more reactants, failure to obtain the desired concentration of the polyisocyanate material in the pouch due to incomplete transfer, spillage, etc.
It would be desirable to avoid the potential hazards and uncertainties of opening separate containers of reactive components in order to transfer the contents one container into the other.